Managing a number of ethernet links

ABSTRACT

A method for managing a number of Ethernet links includes identifying a number of Ethernet links to utilize a number of channels of a cable based on a number of capabilities and a number of policies of a number of media access controllers (MACs) and a number of physical layer entities (PHYs), determining a number of Ethernet link types to be configured for the cable based on the capabilities and policies of the MACs and PHYs, negotiating a number of parameters to allow multi-channel ports of a number of nodes connected to the cable to establish communications through the Ethernet links based on the determined Ethernet link types and the utilized channels, and managing the cable configuration describing the MACs to be supported by the channels within the cable based on the policies.

BACKGROUND

Ethernet links are used to connect devices to form a network to exchangedata. Ethernet links are specified to operate over a number oftransmission media such as co-ax cable, fiber optic cable, andtwisted-pair cable. Ethernet links are also specified to operate at anumber of data rates such as 10 megabits per second (Mb/s), 100 Mb/s, 1gigabit per second (Gb/s), 10 Gb/s, 40 Gb/s, or 100 Gb/s, for example. Anumber of Ethernet physical layer entities (PHY) types are specifiedusing various encodings to support the various transmission media, datarates, and distances. In the case of twisted-pair cable used forEthernet links, the twisted pair cable comprises eight wires in thecable formed into four balanced twisted-pairs. In the case of fiberoptic cable used for Ethernet links, there may be one, two or multipleof either single-mode or multi-mode fibers in the cable. The Instituteof Electrical and Electronics Engineers (IEEE) 802.3 Ethernet standarddefines a function termed “auto-negotiation” for passing configurationinformation from one PHY to another PHY on a link as part of the linkstart-up sequence. Auto-negotiation provide for the PHYs at the ends ofan Ethernet link to exchange their abilities and then commence operationat their highest common operating ability. Auto-negotiation is specifiedfor operation on twisted-pair as well as certain fiber optic links.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various examples of the principlesdescribed herein and are a part of the specification. The examples donot limit the scope of the claims.

FIG. 1 is a diagram of a system for managing multiple Ethernet links ona cable, according to one example of principles described herein.

FIG. 2 is a diagram of a twisted-pair cable connected between two MACsvia the PHY and connector of the two nodes depicted in FIG. 1, accordingto one example of principles described herein.

FIG. 2A is a diagram of a fiber cable connected between two MACs via thePHY and connector of the two nodes depicted in FIG. 1, according toanother example of principles described herein.

FIG. 3 is a diagram of a multi-channel port connected to a cable,according to one example of principles described herein.

FIG. 4 is a flowchart of a method for managing multiple Ethernet linkson a cable, according to one example of principles described herein.

FIG. 5 is a flowchart of a method for managing multiple Ethernet linkson a cable, according to one example of principles described herein.

FIG. 6 is a diagram of a managing system, according to one example ofprinciples described herein.

FIG. 7 is a diagram of a managing system, according to one example ofprinciples described herein.

FIG. 8 is a diagram of an organizationally unique identifier (OUI) nextpage message, according to one example of principles described herein.

FIG. 9 is a diagram of an organizationally unique identifier (OUI) nextpage message comprising 20 bits of user-defined code, according to oneexample of principles described herein.

Throughout the drawings, identical reference numbers designate similar,but not necessarily identical, elements.

DETAILED DESCRIPTION

As mentioned above, Ethernet links are specified to operate over anumber of transmission media, such as co-ax cable, fiber optic cable andtwisted-pair cable, and at a number of data rates such as 10 Mb/s, 100Mb/s, 1 Gb/s, 10 Gb/s, 40 Gb/s, or 100 Gb/s. Certain families ofEthernet PHY types, that support multiple data rates over the sametransmission medium, provide a function to resolve to a highest commondenominator Ethernet PHY type at link initialization based on advertisedEthernet PHY type data rate, and other capabilities, of the two deviceson the Ethernet link. This function is termed auto-negotiation. One suchfamily of Ethernet PHY types is the 10BASE-T, 100BASE-T, 1000BASE-T,10GBASE-T family supporting operation at data rates of 10 Mb/s, 100Mb/s, 1000 Mb/s and 10 Gb/s respectively over a twisted-pair medium.Another such family of Ethernet PHY types is the 1000BASE-X familysupporting operation at 1000 Mb/s over a fiber optic medium. At linkinitialization, auto-negotiation occurs using a modified form of10BASE-T link pulse signaling over two out of, for example, a total offour twisted-pairs of the twisted-pair cable. Once complete, and thehighest common denominator Ethernet PHY type has been selected, data maybe exchanged over the Ethernet link using two or more of thetwisted-pairs of the twisted-pair cable, dependent on the Ethernet PHYtype selected.

Once the link is initialized, and auto-negotiation is complete, the datarate at which data is exchanged remains constant, until the link isterminated. For example, if the data rate selected is 10 Gb/s, the datarate remains at 10 Gb/s until the communication link is terminated.Running a communication link at a 10 Gb/s link speed, when thecommunication link could be reduced to a 100 Mb/s link speed and stillmeet traffic demands, may not be energy efficient.

The principles described herein include a method for managing multipleEthernet links on a single cable and multiple Ethernet links acrossmultiple cables. Such a method includes identifying when the a singlecable may be used to support multiple Ethernet links based on thecapabilities of the devices connected; determining the number ofEthernet links that should operate based on the capabilities andpolicies of the devices connected; negotiating parameters to allow oneor multiple Ethernet links to operate over the cable, whether the cablecontains copper or fiber, based on the capabilities and policies of thedevices connected; and managing, in real-time, the multiple Ethernetlinks in the cable based on a number of policies. Such a method allowsmultiple Ethernet links to use a single cable such that the Ethernetlinks may be powered on or off in real-time. As a result, communicationthrough the cable may be more energy efficient while maintaining atraffic demand.

Further, the method may include determining the length of the cable todetermine the allocation of the number of the multiple Ethernet linksand their data rates to allow communications over the cable. Determiningthe length of the cable will be described in more detail below.

In the present specification and in the appended claims, the term“Ethernet link” is meant to be understood broadly as an act of allowingmedia access controllers (MACs) to establish a separate link includingMAC and PHY functions, to enable to exchange of data over the cable. Inone example, an Ethernet link may provide a link between nodes directlyutilizing a number of channels in a cable. In another example, anEthernet link may provide a link between nodes utilizing a singlechannel in a cable

In the present specification and in the appended claims, the term “node”is meant to be understood broadly as a device that exchanges data over acable. In one example, a node may include user devices such as laptops,desktops, servers, other user computing devices, or combinationsthereof. In another example, nodes may include switches, routers, accesspoints, gateways, or other network interconnecting devices, orcombinations thereof. Further, the first end of the cable may beconnected to a first node and the second end of the cable may beconnected to a second node. In one example, the first end of the cablemay be connected to a MAC of a first node, via the connector and PHY,and the second end of the cable may be connected to a MAC, via aconnector and PHY, of a second node. A cable may have multiple channelsin it, and, therefore, with multiple channels the cable can support oneof more Ethernet links depending on the characteristics of the channeland the operating speed of the link. In this example, the MACs may bemulti-MACs described herein.

In the present specification and in the appended claims, the term“channel” is meant to be understood broadly as a logical connection overa medium. A channel is used to convey an information signal, forexample, a digital bit stream at the PHY level, from one node to anothernode. As an example, in the context of Ethernet communications, achannel may be a pair of wires, formed into a balanced twisted-pair(TP), in a cable containing copper wires, to allow nodes to exchangedata. In another example, a channel may be a wavelength of light(lambda) on a fiber within a cable. In one example, a twisted-pair cableincludes four twisted-pairs, and a single Ethernet link may utilize one,two, or four twisted-pairs in the cable in either simplex or duplex modeto allow nodes to exchange data over the cable. As a result, the nodesmay exchange data over a cable on up to four channels in a twisted-paircable.

The up to four channels of a twisted-pair cable may be configured as asingle Ethernet link or up to four separate Ethernet links. In anotherexample, in the context of Ethernet when the cable contains fiber, achannel provides a bit stream by utilizing a wavelength in a set of anumber of wavelengths sent along the fiber contained within a singlecable. A single wavelength can be configured as a single Ethernet linkor multiple wavelengths can be configured as a single Ethernet link. Inone example, the cable may be configured, for both twisted-pair andfiber cables, to have a number of channels dedicated to bit streams inone direction, and others of a number of channels dedicated to bitstreams in the other direction. In this example, bit streams in a firstdirection are dedicated to transmit from Node A's transmit to Node B'sreceive, and bit streams in a second direction are dedicated to transmitfrom Node B's transmit to Node A's receive.

Further, as used in the present specification and in the appendedclaims, the term “engine” is meant to be understood broadly as a numberof hardware devices, or combination of a number of hardware devices andexecutable instructions used to bring about the functionality describedherein. In an example of an engine comprising a hardware device, thehardware device may be, for example, a number of application specificintegrated circuits (ASICs). In an example of an engine comprisinghardware devices and executable instructions, the hardware device maybe, for example, a number of processors, and the executable instructionsmay be stored in a data storage device and executed by the processors.

Still further, as used in the present specification and in the appendedclaims, the term “a number of” or similar language is meant to beunderstood broadly as any positive number comprising 1 to infinity; zeronot being a number, but the absence of a number.

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present systems and methods. It will be apparent,however, to one skilled in the art that the present apparatus, systems,and methods may be practiced without these specific details. Referencein the specification to “an example” or similar language means that aparticular feature, structure, or characteristic described in connectionwith that example is included as described, but may not be included inother examples.

Referring now to the figures, FIG. 1 is a diagram of a system (100) formanaging multiple Ethernet links on a cable, according to one example ofprinciples described herein. As will be described below, a managingsystem identifies a cable configuration to utilize multiple channels ofa cable based on capabilities of the network connections of nodesconnected to the cable. Further, the managing system (106-1, 106-2,106-3) located on node one (102-1), node two (102-2), as a separatethird part managing system (106-3), or combinations thereof manages, inreal-time, the channels within the cable based on a number of policies.Node one (102-1) and node two (102-2) are computing devices or networkinterconnecting devices that comprise, among other elements, a processorand memory in order to perform the functions described herein.

As illustrated in FIG. 1, the system (100) includes node one (102-1) andnode two (102-2). In this example, node one (102-1) establishes acommunication link to node two (102-2). As illustrated, thecommunication link may be made over a direct link (104). In keeping withthe given example, the direct link (104) may be a cable and a number ofthe communication links are Ethernet links. The cable includes multiplechannels to allow node one (102-1) to establish an Ethernet link withnode two (102-2). Once the Ethernet link is established between node one(102-1) and node two (102-2), the nodes (102) may exchange data via thecable (104).

As illustrated in FIG. 1, the system (100) further includes a managingsystem (106). In one example, the managing system (106) identifies acable configuration to utilize multiple channels of a cable based oncapabilities of the network connections of the nodes connected to thecable (104). In this example, the managing system (106) identifies anEthernet link for node one (102-1) and node two (102-2) via the channelswithin the cable (104).

The managing system (106) further determines a cable configuration forthe cable based on the capabilities and policies of the networkconnections such as the MACs (108-1, 108-2) and PHYs (109-1, 109-2), ofthe nodes at both ends of the cable (104). As will be described in otherparts of this specification, a configuration may be controlled by acentral management or a port management managing system.

The managing system (106) negotiates parameters to allow the networkconnections of the nodes (102) to establish communications through themultiple channels created by utilization of a number of twisted pairs orthrough a number of wavelengths on the fiber of the cable, based on thecapabilities and policies of the MACs (108-1, 108-2) and PHYs (109-1,109-2) at both ends of the cable (104), which will determine what typescan be supported. As will be described in later parts of thisspecification, the communication may be through one channel of the cableor up to four channels of the twisted-pair cable and through a number ofwavelengths on a fiber for fiber optic cables.

The managing system (106) further manages, in real-time, the multipleavailable channels of the cable based on a number of policies. Moreinformation about the managing system (106) will be described in detaillater on in this specification.

While this example has been described with reference to the managingsystem being located over the network, the managing system may belocated in any appropriate location according to the principlesdescribed herein. For example, the managing system may be located innode one (102-1) as indicated by element 106-1, node two (102-2) asindicated by element 106-2, as a separate third part managing system asindicated by element 106-3 on a server, other locations, or combinationsthereof.

As depicted in FIG. 1, node one (102-1) and node two (102-2) comprisemedia access controllers (MACs), elements 108-1 and 108-2, respectively;physical layer entities (PHYs) (109-1, 109-2); and connectors (110-1,110-2) to join electrically or optically and physically the cable (104)to the respective nodes (102-1, 102-2). The MACs (108-1, 108-2) and PHYs(109-1, 109-2) provide for the exchange of data over the direct link(104), via connectors (110-1, 110-2). The MACs (108-1, 108-2) utilizemedia access control (MAC) data communication protocol which is asub-layer of the data link layer, which itself is layer 2 of the OpenSystems Interconnection (OSI) model. The MAC sub-layer providesaddressing and channel access control mechanisms that make it possiblefor network nodes to communicate. In one example, the present systemsand methods is full-duplex Ethernet is utilized in which point-to-pointcommunication between two nodes is supported, and communications betweenmore than two nodes is supported through the use of switches. Thehardware that implements the MAC data communication protocol is the MACs(108-1, 108-2). In one example, the MACs (108-1, 108-2) of FIG. 1 may bemulti-MACs as described below in connection with FIG. 3.

Further, as depicted in FIG. 1, node one (102-1) and node two (102-2)comprise Ethernet physical transceivers (PHY), elements 109-1 and 109-2,respectively. The PHYs (109-1, 109-2) are components that operate at thephysical layer of the OSI network model. The PHYs (109-1, 109-2)implement the Ethernet physical layer portion of the standard, forexample 1000BASE-SX, 1000BASE-T, 100BASE-TX, and 10BASE-T, andimplements the hardware send and receive function of Ethernet framesspecific for the media, data rates and distance. The PHYs (109-1, 109-2)further interface to the line modulation at one end and binary packetsignaling at the other. Functions like MAC addressing are implemented bythe MACs (108-1, 108-2).

As depicted in FIG. 2, node one (102-1) and node two (102-2) compriseconnectors, elements 110-1 and 110-2, respectively. In one exampledepicted in FIG. 2, the connectors (110-1, 110-2) are RJ-45 physicalconnectors for twisted-pair cable. In one example, the RJ-45 connectors(110-1, 110-2) are standardized as the IEC 60603-7 8P8C modularconnector with different categories of performance, with all eightconductors present. The RJ-45 connectors (110-1, 110-2) are an 8position 8 contact (8P8C) connector. An 8P8C connector is a modularconnector used to terminate twisted-pair cable, and may be used forEthernet links over twisted pair and other applications involvingunshielded twisted pair, and shielded twisted pair. An 8P8C connectorhas two paired components: the male plug and the female jack, each witheight equally-spaced conducting channels. When an 8P8C plug is matedwith an 8P8C jack, the contacts meet and create an electricalconnection. Node one (102-1) and node two (102-2) communicate via theRJ-45 connectors (110-1, 110-2) and the cable (104). Thus, for atwisted-pair cable, the RJ-45 connectors (110-1, 110-2) connect thecopper wires in the cable (104) to a number of etches on the circuitboard of the node (102-1, 102-2).

In another example depicted in FIG. 2A, the connectors (210-1, 210-2)are mechanical transfer registered jack (MT-RJ) connectors (210-1,210-2) for use in optical fiber Ethernet communications. In one example,the MT-RJ connectors (210-1, 210-2) are standardized as IEC 61754-18duplex multimode connections. Thus, for a fiber cable (FIG. 2A, 216) theconnectors (110-1, 110-2) tunnel the optical signal from the transmitteron the nodes (102-1, 102-2) into the cable (FIG. 2A, 216) and from thecable to a photo receiver on the nodes (102-1, 102-2).

The PHYs (109-1, 109-2) take the electrical or optical signals, andconvert them to a Media Independent Interfaces (Mils) (230-1, 230-2,231-1, 231-2) to interface with the MAC as specified in IEEE 802.3. Inthe example of FIG. 2, two Mils (230-1, 230-2, 231-1, 231-2) aredepicted. Thus, in one example where the MACs (108-1, 108-2) of FIG. 2are multi-MACs as described below in connection with FIG. 3, a pluralityof Mils (230-1, 230-2, 231-1, 231-2) are present within the system. AMII (230-1, 230-2, 231-1, 231-2) is an interface specified by IEEE 802.3Ethernet standard, and provides the interface between the MAC (108-1,108-2) functions and the PHY (109-1, 109-2) functions. In the example ofFIG. 2, the most channels possible for the copper twisted-pair cable(206) is four due to a limit of four twisted-pairs. Thus, although onlytwo MIIs (230-1, 230-2, 231-1, 231-2) are depicted in FIG. 2, a total offour MIIs (230-1, 230-2, 231-1, 231-2) may be present and utilized asindicated by two dots between the MIIs (230-1, 230-2, 231-1, 231-2). Inthe example of FIG. 2A were a fiber optic cable (216) is used, there mayexist, for example, 8, 16, 64, 128, or more lambdas (λ-1, λ-2), or anynumber of wavelengths that may reside on a number of fibers (222-1,222-2) of a single cable (216), each providing a channel to be assignedits use. In this example, the three dots between the MIIs (230-1, 230-2,231-1, 231-2) represent the many possible MIIs (230-1, 230-2, 231-1,231-2).

Although mentioned above in some aspects, FIG. 2 is a diagram (200) of atwisted pair cable (206) connected between two MACs (108-1, 108-2) ofthe two nodes (102-1, 102-2) depicted in FIG. 1, according to oneexample of principles described herein. As mentioned above, the managingsystem (106-1, 106-2, 106-3) negotiates parameters to allow the nodes toestablish communications through multiple channels of the cable based onthe communication link type(s) selected. In one example, negotiationincludes finding the best match of a set of parameters of each end ofthe cable. Further, the managing system manages, in real-time, utilizesthe channels of the cable based on a number of policies.

As illustrated in FIG. 2, a twisted-pair cable (206) is used toestablish a communication link between MAC (108-1) of node one (102-1)and MAC (108-2) of node two (102-2). In one example, a first end of thecable (206) is connected to the node one (102-1) utilizing, in thisexample, the RJ-45 connector (110-1), PHY (109-1), and MAC (108-1); andthe second end of the cable (206) connected to node two (102-2)utilizing the RJ-45 connector (110-2), PHY (109-2), and MAC (108-2). Inone example, the MACs (108-1, 108-2) of FIG. 2 may be multi-MACs asdescribed below in connection with FIG. 3.

As mentioned above, a number of two wire pairs, called a twisted-pair(212), in a cable (206), are provided to allow nodes to exchange data.In one example, the cable (206) includes four twisted-pairs (212-1,212-2, 212-3, 212-4) to allow the MACs (108) to exchange data over thecable (206).

In one example, the cable (206) may include a number of conductors(210). In one example, the conductors (210) are copper conductors. Inone example, each twisted-pair (212-1, 212-2, 212-3, 212-4) comprisestwo conductors (210). As illustrated, twisted pair (212-1) comprisingconductors 210-1 and 210-2 may be used as a first channel of the cable(206). Twisted-pair (212-2) comprising conductors 210-3 and 210-4 may beused as a second channel of the cable (206). Twisted-pair (212-3)comprising conductors 206-5 and 206-6 may be used as a third channel ofthe cable (206). Twisted-pair (212-4) comprising conductors 206-7 and206-8 may be used as a fourth channel four of the cable (206). As aresult, the MACs (108) may exchange data over the cable (206) on up tofour channels per cable (206) by utilizing the twisted-pairs (212-1,212-2, 212-3, 212-4). Further, the exchange of data may occur in simpleor duplex mode. The twisted pairs (212-1, 212-2, 212-3, 212-4) will becollectively referred to herein as element (212). In one example, anEthernet link may utilize two channels on two twisted-pairs in simplexmode, for example, 212-1 and 212-2. In yet another example, a singleEthernet link is configured that may utilize all four channels ontwisted-pairs in duplex mode (212-1, 212-2, 212-3, 212-4). The initialselection is based on the best capabilities supported by both MACs(108-1, 108-2) and PHYs (109-1, 109-2) at each end of the cable (206).

As depicted in FIG. 2, each of the twisted pairs (212) may be connectedto a number of pins (204) of the RJ-45 connector (110-1) and a number ofpins (208) of RJ-45 connector (110-2). For example, pin (204-1) and pin(204-2) of RJ-45 connector (110-1) are connected to pin (208-1) and pin(208-2) of RJ-45 connector (110-2) via twisted pair (212-1) of the cable(206). Further, pin (204-3) and pin (204-6) of RJ-45 connector (110-1)are connected to pin (208-3) and (208-6) of RJ-45 connector (110-2) viatwisted pair (212-2) of the cable (206). Further, pin (204-4) and pin(204-5) of RJ-45 connector (110-1) are connected to pin (208-4) and(208-5) of RJ-45 connector (110-2) via twisted pair (212-3) of the cable(206). Further, pin (204-7) and pin (204-8) of RJ-45 connector (110-1)are connected to pin (208-7) and pin (208-8) of RJ-45 connector (110-2)via twisted pairs (212-4) of the cable (206).

The MAC (108-1) is communicatively coupled to pins (204) via PHY(109-1), and MAC (108-2) is communicatively coupled to pins (208), viaPHY (109-2). The communication interface between MAC (108) and the PHY(109) is via a Media Independent Interfaces (MII) (230-1, 230-2, 231-1,231-2). The number of separate MIIs (230-1, 230-2, 231-1, 231-2)established is equal to the number of Ethernet links configured on thecable (206). In this example of a twisted-pair cable (206), one, two,three, or four separate Ethernet links can be configured which wouldresult in one, two, three, or four MIIs (230-1, 230-2, 231-1, 231-2)established between the MAC (108) and PHYs (109).

As mentioned above, the managing system (106-1, 106-2, 106-3) manages,in real-time, the multiple twisted-pairs of the cable based on a numberof policies. As illustrated, the cable (206) has up to four channels forwhich the twisted-pairs (212) are utilized. In one example, thecommunication may be through one channel of the cable or up to fourchannels of the cable.

For example, according to the policies, the communication may be throughtwisted-pair (212-1) of the cable. In keeping with the given example,the communication may be through twisted-pair (212-1) and twisted-pair(212-2) of the cable at a later time, according to the policies. Instill the same example, the communication may be through twisted-pair(212-1), twisted-pair (212-2), twisted-pair (212-3), and twisted-pair(212-4) of the cable at an even later time, according to the policies.As a result, the multiple twisted-pairs (212) of the cable (206) may beutilized such that the multiple channels may be powered on or off inreal-time according to the policies. Thus, communication through themultiple twisted-pairs (212) may be more energy efficient whilemaintaining a traffic demand. More information about managing, inreal-time, the multiple twisted-pairs of the cable based on a number ofpolicies will be described below.

FIG. 2A is a diagram (250) of a fiber cable (216) connected between twoMACs (108-1, 108-2) via the PHYs (109-1, 109-2) and connectors (210-1,210-2) of the two nodes depicted in FIG. 1, according to another exampleof principles described herein As illustrated in FIG. 2A, a fiber opticcable (216) is used to establish a communication link between MAC(108-1) of node one (102-1) and MAC (108-2) of node two (102-2). Thefiber optic cable (216) may comprise a number of fibers (222-1, 222-2)that can support a number of wavelengths of light (lambdas (λ)), eachproviding a channel to be assigned its use. In the example of FIG. 2A,two fibers (222-1, 222-2) are depicted within the fiber optic cable(216). However, any number of fibers (222-1, 222-2) may be present andused within the fiber optic cable (216).

In one example, a first end of fiber optic cable (216) is connected tothe node one (102-1) utilizing MT-RJ connector (210-1), PHY (109-1), andMAC (108-1), and a second end of fiber optic cable (216) is connected tonode two (102-2) utilizing MT-RJ connector (210-2), PHY (109-2), and MAC(108-2).

Fiber optic cables can have various connector types, use different typesof fibers (222-1, 222-2), and can carry a single wavelength (A) ormultiple wavelengths of light. In one example of FIG. 2A, a pair offibers and a single frequency may be used to provide the bit streams. Inanother example of FIG. 2A, a single fiber (222-1, 222-2) with multiplewavelengths (λ) may be used to provide the bit streams. In still anotherexample of FIG. 2A, multiple wavelengths or either a single or pair offibers (222-1, 222-2) may be used to create multiple channels coexistingon the fiber at different wavelengths (λ). As a result, the MACs (108)may exchange data over the fiber optic cable (216) on multiple channels(8, 16, 64, . . . ) per fibers (222-1, 222-2) of the fiber optic cable(216) by utilizing the multiple wavelengths (λ) to provide the multipleseparate Ethernet links.

The MAC (108-1) is communicatively coupled to the MT-RJ connector(210-1) via PHY (109-1), and MAC (108-2) is communicatively coupled tothe MT-RJ connector (210-2), via PHY (109-2). The communicationinterface between the MAC (108) and the PHY (109) is via the number ofMIIs (230-1, 230-2, 231-1, 231-2). In the example of FIG. 2A, two MIIs(230-1, 230-2, 231-1, 231-2) are depicted. Thus, in one example wherethe MACs (108-1, 108-2) of FIG. 2A are multi-MACs as described below inconnection with FIG. 3, a plurality of MIIs (230-1, 230-2, 231-1, 231-2)are present within the system. The number of separate MIIs (230-1,230-2, 231-1, 231-2) established is equal to the number of Ethernetlinks configured on the cable (216). In this example of a fiber opticcable (216), one, two, eight, sixteen, sixty four, or more separateEthernet links can be configured which would result in one, two, eight,sixteen, sixty four, or more MIIs (230-1, 230-2, 231-1, 231-2)established between the MAC (108) and PHYs (109).

FIG. 3 is a diagram of a multi-channel port (302) connected to a cable(306), according to one example of principles described herein. Asmentioned above, the managing system (106-1, 106-2, 106-3) negotiatesparameters to allow the nodes to establish communications through anumber of channels, 1 to N, of the cable (306) based on the capabilitiesand policies of the MACs (108, 308) and PHYs (109, 309) at both ends toestablish a number of cable configurations. Further, the managing system(106-1, 106-2, 106-3) manages, in real-time, the multiple twisted-pairsor wavelengths of light (λ) within the cable (306) based on a number ofpolicies.

As illustrated, a multi-channel port (302) is connected to a cable(306). In one example, the multi-channel port (302) may be hardware usedby a node (102-1, 102-2). Further, in this example, the cable (306)includes 1 to N channels (314-1 through 314-N) analogous to thetwisted-pairs (212) of FIG. 2 and lambdas (λ) (222) of FIG. 2A. Further,the multi-channel port (302) has at least one transmit queue and atleast one receive queue per active Ethernet link, and may also supportmultiple queues per channel for quality of service (QoS), separation, orother policy purposes for each Ethernet link. In one example, themanaging system (316) provides the desired configuration information tothe Traffic Control Operational Process (TCOP) (304) which controls themulti-MAC (308) to manage the four twisted-pairs (314) in real-time. TheTCOP (304) is coupled to the multi-MAC (308) via, for example, anelectrical connection (311). For example, the managing system (316)provides the desired configuration information to the TCOP (304) totransition an operational mode of the multi-MAC (308) from a currentconfiguration state to a desired configuration state according to anumber of policies. In one example, transition an operational mode ofthe multi-MAC (308) from a current configuration state to a desiredconfiguration state may be accomplished through the use of a cableconfiguration-Desired module (Cable Config Desired) (340) and cableconfiguration-Present module (Cable Config Present) (330), as will bedescribed in more detail below.

As illustrated, the multi-channel port (302) includes a Traffic ControlOperational Process (TCOP) (304). The TCOP (304) is used to transferpackets of data to and from the receive and transmit queues. Further,the TCOP (304) controls the operational modes each of the one to Nchannels (314) of the cable (306). In one example, the operational modesmay include allowing at least one of the N channels (314) to power on oroff according to policies.

The multi-channel port (302) includes a multi-media access controller(Multi-MAC) (308). In one example, the TCOP (304) queues traffic to andfrom the multi-MAC (308) in a manner that adheres to a number of trafficpolicies. The TCOP (304) further instructs the multi-MAC (308) aboutusage of the N number of channels (314), the association of the Nchannels to the M number of MACs (308-1 through 308-M), and how toutilize each of the 1 to N channels (314-1 through 314-N) to support the1 to M MACs (308-1 through 308-M) via the 1 to M MIIs (230-1 through230-M). The TCOP (304) further instructs the multi-MAC (308) about howto transmit and receive data over one of more Ethernet links within thecable (306). The TCOP (304) comprises a cable configuration-Desired(Cable Config Desired) module (340) and cable configuration-Present(Cable Config Present) module (330). The Cable Config Desired (340)describes how the resources within the cable (306) should be configured,and the Cable Config Present (330) describes the present configurationof the resources within the cable (306). The cable configurationcontains the number and type of MACs (308-1 through 308-M) configured,and how each of the MACs (308-1 through 308-M) utilize a number ofchannels (314-1 through 314-N) to communicate across the cable.

Further, the TCOP (304) instructs the multi-MAC (308) about theassociation of internal queues for at least one of the MACs (308-1through 308-M). In one example, the multi-MAC (308) utilizes a number ofthe 1 to N channels (314-1 through 314-N) in a variety of ways. Forexample, the multi-MAC (308) utilizes twisted-pairs (212-1, 212-2,212-3, 212-4) in the context of a copper twisted-pair cable (206) ofFIG. 2 to run separate Ethernet links on each single twisted pair (212).In another example, the multi-MAC (308) utilizes all four-twisted pairchannels (212-1, 212-2, 212-3, 212-4) for a single high speedcommunication Ethernet link. Further, the multi-MAC (308) may utilizeany combination of single pair and/or multiple pair for each Ethernetlink for data transfer across the copper twisted-pair cable (206). As aresult, at least one of the N channels (314-1 through 314-N) of thecable (216) may be utilized such that at least one of the N channels(314-1 through 314-N) and associated MACs (308-1 through 308-M) may bepowered on or off in real-time according to the policies via themulti-MAC (308). As a result, communication through the multiplechannels may be more energy efficient while maintaining a trafficdemand.

FIG. 4 is a flowchart of a method for managing multiple Ethernet linkson a cable (104, 206, 216, 306), according to one example of principlesdescribed herein. In one example, the method (400) may be executed bythe system (300) of FIG. 3. In other examples, the method (400) may beexecuted by other systems described herein such as, for example, thesystem (100) of FIG. 1, the system (200) of FIG. 2, the system (250) ofFIG. 2A, managing system (600) of FIG. 6 described below, memoryresources (700) of FIG. 7 also described below, or combinations thereof.

In one example, the method (400) includes identifying (401) a number ofEthernet links to utilize a number of channels of a cable based on anumber of capabilities and a number of policies of a number of MACs(108, 308) and a number of PHYs (109, 309) at both nodes (102-1, 102-2,302) connected to the cable (104, 206, 216, 306). The method furtherincludes determining (402) a number of Ethernet link types to beconfigured for the cable based on the capabilities and policies of theMACs and PHYs.

The method further includes negotiating (403) a number of parameters toallow the node's multi-channel ports to establish communications througha number of Ethernet links (1-M) utilizing a number of channels (1-N)across the cable based on the identified number of Ethernet link typesand the utilization of a number of channels (1-N) that support theselected Ethernet link(s). In one example, the utilized channels arethose channels recorded as a desired cable configuration. The methodfurther includes managing (404), in real-time, the cable configurationdescribing a number of MACs (1-M) to be supported by a number ofchannels (1-N) within the cable based on a number of policies.

As mentioned above, the method (400) includes identifying (401) a numberof Ethernet links to utilize a number of channels through a number oftwisted-pairs (212-1, 212-2, 212-3, 212-4) or wavelengths (λ) of a cable(104, 206, 216, 306) based on a number of capabilities and a number ofpolicies of the MACs (108, 308) at both nodes (102-1, 102-2, 302)connected to the cable (104, 206, 216, 306). In one example, themanaging system (106, 316) identifies if one node (102-1, 102-2, 302) isconnected to another node (102-1, 102-2, 302). If one node (102-1,102-2, 302) is connected to another node (102-1, 102-2, 302), the method(400) identifies that a communication link is available. Alternatively,if one node (102-1, 102-2, 302) is not connected to another node (102-1,102-2, 302), the method (400) identifies that a communication link isnot available.

Further, depending on the nodes' (102-1, 102-2, 302) multi-channel port(302), multiple channels of the cable (104, 206, 216, 306) may beutilized to establish Ethernet link communications through the multiplechannels. For example, if it is determined that the nodes (102-1, 102-2,302) connected to a cable (104, 206, 216, 306) may utilize multipletwisted-pairs (212) or wavelengths (λ) of the cable (104, 206, 216,306), the method (400) identifies a number of Ethernet links for thenodes as being able to utilize a number of channels (i.e., twisted-pairs(212) or wavelengths (λ)) of a cable (104, 206, 216, 306).Alternatively, if it is determined that the MACs (108, 308) of the nodes(102-1, 102-2, 302) connected to a cable (104, 206, 216, 306) cannotutilize a number of channels (i.e., twisted pairs (212) or wavelengths(λ)) of a cable, the method (400) does not identify a Ethernet link forthe nodes as being able to utilize a number of channels (i.e., twistedpairs (212) or wavelengths (λ)) of the cable (104, 206, 216, 306), and,instead, uses a single channel.

Further, the managing system (106, 316) may utilize and extend the IEEE802.3 Ethernet standard function termed “auto-negotiation” for passingconfiguration information from one PHY (109, 309) to the other on a linkas part of the Ethernet link start-up sequence. Auto-negotiationprovides for the PHYs (109-1, 109-2, 309-1, 309-2) at the ends of acable (104, 206, 216, 306) to exchange their abilities and then commenceoperation at their highest common operating ability. Auto-negotiation isspecified for operation on twisted-pair cable as well as certain fiberoptic links described herein.

This standard function is extended to identify not just one, but rathera number of Ethernet links which utilize a number of channels within acable based on MACs (108, 308) and PHYs (109, 309) of the nodesconnected to the cable (104, 206, 216, 306). In one example, theauto-negotiation function is extended utilizing a ‘next page’ functionthat is defined in the IEEE standards. The next page function allows thetransfer of arbitrary data between two devices on a link after the basicconfiguration information has been exchanged but prior to the link goinginto operation including exchange of addressed data packets. There aretwo types of auto-negotiation next page encoding. One type ofauto-negotiation next page encoding is referred to as “message” pages,and another type of auto-negotiation next page encoding is referred toas “unformatted” pages. A next page message exchange includes theexchange of a message page and a number of unformatted pages. Themessage page defines the type of next page exchange taking place by themessage code it contains. The number of unformatted pages that follow isdetermined by the particular next page message code.

Turning again to the figures, FIG. 8 is a diagram of an organizationallyunique identifier (OUI) next page message (800), according to oneexample of principles described herein. The 48-Bit universal MACaddress, used in Ethernet as the Ethernet MAC address comprises twoparts. These parts are defined by the IEEE 802-2001 standard. The first24 bits correspond to the Organizationally Unique Identifier (OUI)assigned by the IEEE. The second part, comprising the remaining 24, isadministered locally by the assignee. When a device is manufactured, theOUI is combined with a 24 bit, locally administered value which isregistered as used so it can never be used again. In this way a unique48 bit MAC address is formed. As can be seen once 2²⁴ (nearly 17million) units are manufactured using a particular OUI the assignee hasto return to the IEEE and request a new OUI.

The OUI Next Page message exchange allows the transfer of an OUI, andrelated user-defined user codes, from a far end device. The transfer ofthese user-defined user codes within the OUI Next Page message exchangecan be used to determine the ability to operate multiple Ethernet linkson a single cable, and on start-up, which of those multiple Ethernetlinks should operate. As the user-defined user codes are related to theOUI, that is, if the OUI is known to the receiving device, can theuser-defined codes transferred be interpreted. This mechanism is not amulti-vendor approach. If, for example, another vendor's equipment wereto receive an OUI Tagged Next Page message from a particular vendor,even if it was able to recognize the OUI as belonging to that particularvendor, it would be unable to decode it because format is defined bythat particular vendor.

As illustrated in FIG. 8, an OUI Next Page message comprises a firstcode, identified as the “message code,” followed by four subsequentcodes, the first to fourth “user codes.” The “header” of each code isfive bits (NP, Ack, MP, Ack2 and T). Within FIG. 8, “NP” indicateswhether or not this is the last next page to be transmitted as definedby the IEEE 802.3-2012, subclause 28.2.3.4.3 standards. “Ack” indicatesthat a device has successfully received its link partner's link codeword as defined by the IEEE 802.3-2012, subclause 28.2.1.2.4 standards.“MP” means “message page” and differentiates a next page message pagefrom a next page unformatted page as defined by the IEEE 802.3-2012,subclause 28.2.3.4.5 standards. “Ack2” indicates that a device has theability to comply with the message as defined by the IEEE 802.32012,subclause 28.2.3.4.6 standards. “T” indicates a toggle bit used toensure synchronization with the link partner during next page exchangeas defined by the IEEE 802.3-1998, subclause 28.2.3.4.7 standards. BitsO₂₃₋₀ constitute the 24 bit organizationally unique identifiers asdefined by the IEEE 802.3-2012, subclause 28C.6 standards. Bits U₁₉₋₀are 20 bit user-defined user code values that is specific to the OUItransmitted as defined by the IEEE 802.3-2012 subclause 28C.6 standards.

Thus, the meanings of the five bits (NP, Ack, MP, Ack2 and T) aredefined in the IEEE 802.3 standards. As indicated above, bits O₂₃ to O₀constitute the 24 bit organizationally unique identifier (OUI). Hence,twenty bits (U₁₉-U₁) remain for the provision of user defined dataassociated with the OUI.

As illustrated in FIG. 8, an OUI next page message (800) comprises afirst code (801), identified as the “message code” followed by foursubsequent codes (802, 803, 804, 805) are first to fourth “user codes.”The “header” of each code (801, 802, 803, 804, 805) comprises five bits(NP, Ack, MP, Ack2 and T), and their meaning is defined in the IEEE802.3 standard as described above.

Since the OUI next page message (800) may also be used for other typesof proprietary information exchange, some of the payload bits of the OUInext page message (800) may be reserved for identifying the type ofproprietary exchange that is taking place. FIG. 9 is a diagram of anorganizationally unique identifier (OUI) next page message comprising 20bits of user-defined code, according to one example of principlesdescribed herein. Bits designated as HP OUI₂₃₋₀ are a 24 bit OUIassigned by the IEEE to Hewlett Packard Company (HP). Bits OP₃₋₀comprise HP defined operation code (Op-Code). Bits D₁₅₋₀ comprise a 16bit user-defined code value that is specific to the HP Op-Codetransmitted. Thus, FIG. 9, using the same bit identifications as in FIG.8, depicts the assignment of the 20 bits of user defined information.The four most significant bits, OP₃ to OP₀, are the Op-Code while theremaining 16 bits, D15 through D₀, provide information specific to theOp-Code. Tables 1 and 2, below, depict an Op-Code assignment accordingto one example of principles described herein.

TABLE 1 Example Op-code Assignments Op Code Meaning 0000 Reserved forfuture use 0001 1-Pair Gigabit Ethernet capability 0010 to 1111 Reservedfor future use

TABLE 2 Example Op-Code specific data for HP Op-Code “0001” Data bitMeaning D₀ Operate 1 Gb/s Ethernet on pair 1 D₁ Operate 1 Gb/s Etherneton pair 2 D₂ Operate 1 Gb/s Ethernet on pair 3 D₃ Operate 1 Gb/sEthernet on pair 4 D₄ to D₁₅ Reserved for future use

In this example, the value “0001,” in association with the applicableHewlett-Packard assigned 24-bit OUI, indicates the capability ofoperating multiple Ethernet links on a single cable (104, 206, 216,306). Information specific to the Op-Code in bits D₁₅ to D₁ are used toconvey, at start-up, which of a number of Ethernet links should operate.

The actual exchange may occur as follows. When the auto-negotiation basepage exchange is complete, the next page exchange, if supported, maycommence. Assuming that the receiving node supports this feature, an OUInext page exchange may commence, and the four next pages may betransferred. Once it is determined that an OUI next page exchange hasoccurred, the OUI supplied is examined. If the OUI is a known OUI, thenthe Op-Code field is examined. If the Op-Code indicates the ability tooperate multiple Ethernet links on a single cable, and assuming thereceiving device is also capable of operating in this mode, the Op-Codespecific data is examined to establish which links may operate at startup. In one example, this is based on a logical “OR” of the links thatthe receiving device and the sending device request.

As mentioned above, the method (400) includes determining (402) a numberof Ethernet link types to be configured for the cable based on the onthe capabilities and policies of the MACs (108, 308) and PHYs (109, 309)at both ends of the communication link. In one example, determining acommunication link type for the cable (104, 206, 216, 306) based on thecapabilities and policies of the MACs (108, 308) and PHYs (109, 309) atboth ends of the communication link includes determining if thecommunication link type utilizes central management or a portmanagement.

In one example, central management manages the communication link at asub-port level by sending specific messages and control messages to thenodes connected to the cable to communicate the desired cableconfiguration. This allows the nodes (102-1, 102-2, 302) to establishcommunications through the multiple channels of the cable (104, 206,216, 306). In keeping with the given example, the multi-channel port(302) management system (316) assigns a number of channels of themultiple possible channels to negotiate the parameters to allow thenodes (102-1, 102-2, 302) to establish communications through themultiple channels of the cable (104, 206, 216, 306).

As mentioned above, the method (400) includes negotiating (403)parameters to allow the nodes (102-1, 102-2, 302) to establishcommunications through the multiple twisted pairs (212) or wavelengths(λ) of the cable (104, 206, 216, 306) based on the capabilities andpolicies of the MACs (108, 308) and PHYs (109, 309) at both ends. Aswill be described below, the managing systems (106, 316) of FIGS. 1, and3 may renegotiate the parameters according to the number of policies ofthe managing system.

In one example, the parameters that are negotiated or centrallyconfigured include a link speed parameter. In this example, the linkspeed parameter allows the node (102-1, 102-2, 302) to communicate withthe other node (102-1, 102-2, 302) at a link speed such as 10 Mb/s, 100Mb/s, 1 Gb/s, 10 Gb/s, 40 Gb/s, or 100 Gb/s via a cable (104, 206, 216,306). In one example, if a number of twisted pairs (212) or a number ofwavelengths (λ) are used to establish communications, the link speeds ofeach of the twisted pairs (212) or wavelengths (λ) may be negotiated tobe 1 Gb/s.

In another example, the parameters may include the number of channelsthat are used via the cable (104, 206, 216, 306). For example, theparameters may specify to use one channel of the cable (104, 206, 216,306). In another example, the parameters may specify to use multiplechannels of the cable (104, 206, 216, 306). For example, channel one,channel two, and channel four created through use of twisted-pairs314-1, 314-2, and 314-4, respectively.

As mentioned above, the method (400) includes managing (404), inreal-time, the number of twisted-pairs (212) or a number of wavelengths(λ) of the cable (104, 206, 216, 306) based on a number of policies. Inone example, managing, in real-time, the twisted-pairs (212) orwavelengths (λ) of the cable based on a number of policies includespowering MACs (108, 308) and PHYs (109, 309) driving the twisted-pairs(212) or wavelengths (λ) of the cable on or off based on the number ofpolicies. For example, the policies may specify that MACs (108, 308) andPHYs (109, 309) that drive twisted-pair (314-1) is powered off whilepowering the MACs (108, 308) and PHYs (109, 309) that are drivingtwisted-pairs 314-3 and 314-4. A similar process may take place with anumber of wavelengths (λ) within fiber optic cable (FIG. 2A, 216). Inanother example, the policies may specify that all possible MACs (108,308) and PHYs (109, 309) that drive either twisted-pairs (212) orwavelengths (λ) are powered on.

In one example, the policies may include a traffic demand policy, aspecific time policy, a power conservation policy, a current parameterpolicy, a change parameter policy, or combinations thereof. The policieswill now be described below.

The traffic demand policy may allow drivers of the twisted-pairs (212)or wavelengths (λ) of the cable (104, 206, 216, 306) to power on and offaccording to a traffic demand. For example, if a traffic demand is high,the traffic demand policy allows the twisted-pairs (212) or wavelengths(λ) of the cable to be driven. For example, all four-twisted pairs of acopper twisted-pair cable (may) may be driven to provide four channelsfor data transfer. In another example, if a traffic demand is low, thetraffic demand policy allows the MACs (108, 308) and PHYs (109, 309)that drive the twisted pairs of the copper twisted-pair cable to poweroff. For example, the MAC and PHY that drives twisted-pair (314-1) arepowered on and the other twisted-pairs are not driven so the associatedMACs and PHYs are powered off. As a result, communication through themultiple twisted-pairs may be more energy efficient while maintaining atraffic demand.

The specific time policy may allow the twisted-pairs (212) orwavelengths (λ) of the cable (104, 206, 216, 306) to power on and offduring a specific time of day. For example, during the night, very fewusers may establish communications via the cable. As a result, duringthe night, multiple twisted pairs (212) or wavelengths (λ) of the cable(104, 206, 216, 306) are not driven according to the specific timepolicy. For example, the MAC (108, 308) and PHY (109, 309) that drivestwisted pair (314-2) may be powered on. Alternatively, during the day,many users establish communications via the cable. As a result, duringthe day, multiple MACs (108, 308) and PHYs (109, 309) that drivetwisted-pairs (212) of the copper twisted-pair cable (104, 206, 306) arepowered on according to the specific time policy. For example, all fourtwisted-pairs may be driven. As a result, communication through themultiple channels may be more energy efficient while maintaining atraffic demand according to the specific time policy.

The power conservation policy may allow the multiple twisted-pairs (212)or wavelengths (λ) of the cable (104, 206, 216, 306) to driven or notaccording to power conservation goals. For example, if a powerconservation policy specifies that power is to be conserved at alltimes, a maximum of two-twisted pairs may be driven at any given time.Alternatively, if a power conservation policy specifies that power isnot to be conserved at all times, all of the twisted-pairs may be drivenat any given time. As a result, communication through the multiplechannels may be more energy efficient according to the powerconservation policy.

The current parameter policy may allow the MACs (108, 308) and PHYs(109, 309) that drive multiple twisted-pairs (212) or wavelengths (λ) ofthe cable (104, 206, 216, 306) to power on and off according to thecurrent parameters. For example, the current parameter may specify thattwo twisted-pairs (212) are to be driven at the current period of time.In another example, the current parameter may specify that alltwisted-pairs (212) are to be driven at the current period of time.

The change parameter policy may allow the multiple MACs (108, 308) andPHYs (109, 309) that drive the twisted-pairs (212) or wavelengths (λ) ofthe cable (104, 206, 216, 306) to power on and off according to changeparameters. For example, the change parameter may specify that twotwisted-pairs are to be utilized at a given future period of time. Inanother example, the change parameter may specify that all twisted-pairsare to be utilized at a given future period of time. As a result, thechange parameter policy allows the managing system to change the currentparameters.

FIG. 5 is a flowchart of an example of a method for managing multipleEthernet links on a cable (104, 206, 216, 306), according to one exampleof principles described herein. In one example, the method (500) may beexecuted by the system (300) of FIG. 3. In other examples, the method(500) may be executed by other systems described herein such as, forexample, the system (100) of FIG. 1, the system (200) of FIG. 2, thesystem (250) of FIG. 2A, managing system (600) of FIG. 6 describedbelow, memory resources (700) of FIG. 7 also described below, orcombinations thereof. In one example, the method (500) includesidentifying (501) an Ethernet link to utilize a number of twisted-pairsor wavelengths of a cable based on the capabilities and policies of theMACs (108, 308) and PHYs (109, 309) of the nodes (102, 302) connected tothe cable (104, 206, 216, 306). The method further determines (502) alength of the cable to determine the Ethernet link types to utilize percable to allow the nodes to establish communications. The method (500)may further comprise determining (503) an Ethernet link type within thecable based on the cable length, capabilities of the MACs and PHYs oneach end of the cable, and traffic needs. The method further negotiates(504) parameters to determine a cable configuration which allows thenodes to establish communications through the channels such as, forexample twisted-pairs or wavelengths of the cable based on thedetermined Ethernet link type(s), and managing (505), in real-time, themultiple channels provided by the twisted pairs or wavelengths withinthe cable based on a number of policies.

As mentioned above, the method (500) includes determining (502) a lengthof the cable to determine the Ethernet link types and number of MACs toutilize multiple channels to allow the nodes to establishcommunications. Thus, block 502 is used to determine a length of thecable to determine the types and number of channels to allocate to allowthe nodes to establish communications. In one example, the length of thecable is used to help determine the allocation of the four channels inthe copper twisted-pair cable (206). If the length of the cable isgreater than a certain length, more twisted-pairs (212) may be utilizedat slower speeds to create two to four channels. In keeping with thegiven example, if the length of the cable (206) is less than a certainlength, a higher speed single channel, utilizing multiple twisted-pairs(212), may be utilized to create one high speed channel.

In another example, the length of a fiber cable (216) may influence thetype of wavelength grouping and type of optical transmitters andreceivers selected and/or configured to create channels. Further, thelength of a fiber cable (216) may influence how to allocate thosechannels to a number of MACs (108, 308).

In another example, depending on the length of the cables, if a singlehigh speed communication link is desired; multiple cables may beutilized. For example, the single high speed communication link mayutilize five cables. In this example, all four twisted pairs of each ofthe five cables may be linked together to create a single high speedcommunication link.

FIG. 6 is a diagram of an example of a managing system (106-1, 106-2,106-3, 316), according to one example of principles described herein.The managing system (600) includes a MAC (108, 308) and PHY (109, 309)capability identifying engine (602), an Ethernet link type determiningengine (604), a parameter negotiating and configuration determiningengine (606), and a managing engine (608). In one example, the managingsystem (600) may also include a length determining engine (610). In oneexample, the engines (602, 604, 606, 608, 610) refer to a combination ofhardware and program instructions to perform a designated function. Inthis example, each of the engines (602, 604, 606, 608, 610) may includea processor and memory. The program instructions are stored in thememory and cause the processor to execute the designated function of theengine. In another example utilizing port management, the engines (602,604, 606, 608, 610) may be implemented as logic stored on a data storagedevice. In still another example, state machines that do not contain aprocessor such as, for example, a number of application specificintegrated circuits (ASICs). In this example, the functionality of theMACs (108, 308) and PHYs (109, 309) described herein may also beimplemented by these ASICs.

The MAC and PHY capability identifying engine (602) identifies thecapabilities of the MACs (108, 308) and PHYs (109, 309) on each end ofthe cable (104, 206, 216, 306). The capabilities describe how each MAC(108, 308) and PHY (109, 309) can utilize the number of twisted-pairs(212) or wavelengths (A), and at what speed. In one example, the MAC andPHY capability identifying engine (602) identifies whether MACs (108,308) and PHYs (109, 309) at each end of the cable can utilize multipletwisted-pairs (212) or wavelengths (λ) of a cable (104, 206, 216, 306).In another example, the MAC and PHY capability identifying engine (602)identifies whether the nodes (102, 302) at either end of the cable (104,206, 216, 306) can utilize multiple twisted-pairs (212) or wavelengths(λ) of multiple cables (104, 206, 216, 306) to form a single channel ormultiple aggregated channels.

The Ethernet link type determining engine (604) determines a number ofcommunication link types for the cable (104, 206, 216, 306) which mayreside at either end of the cable or may be centralized. In one example,the Ethernet link type determining engine (604) determines if a numberof the Ethernet link types has central management or has portmanagement.

The parameter negotiating and configuration determining engine (606)negotiates parameters to allow the nodes to establish communicationsthrough the multiple twisted-pairs (212) or wavelengths (λ) of the cable(104, 206, 216, 306) based on the capabilities and policies of the MACs(108, 308) and PHYs (109, 309) at both ends of the cable. The parameternegotiating and configuration determining engine (606) furtherdetermines the desired cable configuration that describes the negotiatedparameters. In one example, the parameter negotiating and configurationdetermining engine (606) negotiates a link speed parameter as well asthe other parameters described above, and constructs a desired cableconfiguration data element containing these parameters.

The managing engine (608) manages the multiple twisted-pairs (212) orwavelengths (λ) of the cable (104, 206, 216, 306) based on a number ofpolicies. In one example, the managing engine (608) manages the multipletwisted-pairs (212) or wavelengths (λ) of the cable (104, 206, 216, 306)in real time. In another example, the managing engine (608) manages thepowering of the MACs (108, 308) and PHYs (109, 309) that drive themultiple twisted-pairs (212) or wavelengths (λ) of the cable, on or offbased on the number of policies. As mentioned above, the number ofpolicies may include a traffic demand policy, a specific time policy, apower conservation policy, a current parameter policy, a changeparameter policy, other policies, or combinations thereof.

The length determining engine (610) determines a length of the cable(104, 206, 216, 306) to determine the number of multiple channels toallocate to allow the nodes to establish communications. In one example,the length determining engine (610) determines a length of one cable. Inanother example, the length determining engine (610) determines a lengthof the multiple cables. In one example, the length determining engine(610) determines a length of a fiber cable (216). In another example,the length determining engine (610) determines a length of a cable(206).

FIG. 7 is a diagram of an example of a managing system (106-1, 106-2,106-3, 316), according to one example of principles described herein. Inthis example, managing system (700) includes processing resources (702)that are in communication with memory resources (704). Processingresources (702) include at least one processor and other resources usedto process programmed instructions. The memory resources (704) representgenerally any memory capable of storing data such as programmedinstructions or data structures used by the managing system (700). Theprogrammed instructions shown stored in the memory resources (704)include an Ethernet link identifier (706), a central manager (708), aport manager (710), a parameters negotiator and configuration creator(712), a cable length determiner (714), a specific time policy specifier(716), a power policy conserver (718), a current parameter policyspecifier (720), a parameter policy changer (722), and a traffic demandpolicy specifier (724).

The memory resources (704) include a computer readable storage mediumthat contains computer readable program code to cause tasks to beexecuted by the processing resources (702). The computer readablestorage medium may be tangible and/or physical storage medium. Thecomputer readable storage medium may be any appropriate storage mediumthat is not a transmission storage medium. A non-exhaustive list ofcomputer readable storage medium types includes non-volatile memory,volatile memory, random access memory, write only memory, flash memory,electrically erasable program read only memory, or types of memory, orcombinations thereof.

The Ethernet link identifier (706) represents programmed instructionsthat, when executed, cause the processing resources (702) to identify anEthernet link to utilize multiple twisted pairs (212) or wavelengths (λ)of a cable (104, 206, 216, 306) based on nodes (102, 302) connected tothe cable. The central manager (708) represents programmed instructionsthat, when executed, cause the processing resources (702) to manage thecommunication link at a sub-multi-port (MAC) level by sending specificmessages and control messages with the desired cable configuration datato the nodes connected to both ends of the cable containing thenegotiated parameters, to allow the nodes to establish communicationsthrough the one or multiple twisted-pairs (212) or wavelengths (λ) ofthe cable (104, 206, 216, 306). The MAC manager (710) representsprogrammed instructions that, when executed, cause the processingresources (702) to manage the assignment of one channel of the multiplechannels to negotiate the parameters to allow the nodes to establishcommunications through the one or multiple twisted-pairs or wavelengthsof the cable.

The parameters negotiator and configuration creator (712) representsprogrammed instructions that, when executed, cause the processingresources (702) to negotiate parameters and create a configuration toallow the nodes (102, 302) to establish communications through themultiple twisted-pairs or (212) wavelengths (λ) of the cable (104, 206,216, 306) based on the selected Ethernet link type. The cable lengthdeterminer (714) represents programmed instructions that, when executed,cause the processing resources (702) to determine a length of the cableto determine the number of multiple channels to allocate to allow thenodes to establish communications.

The specific time policy specifier (716) represents programmedinstructions that, when executed, cause the processing resources (702)to specify a time to manage, in real-time, the multiple twisted-pairs(212) or wavelengths (λ) of the cable (104, 206, 216, 306) according toa specific time policy. The power policy conserver (718) representsprogrammed instructions that, when executed, cause the processingresources (702) to conserve power by managing, in real-time, the MACs(108, 308) and PHYs (109, 309) that drive the multiple twisted-pairs orwavelengths of the cable according to a power conservation policy. Thecurrent parameter policy specifier (720) represents programmedinstructions that, when executed, cause the processing resources (702)to specify current parameters to manage, in real-time, the MACs (108,308) and PHYs (109, 309) that drive the multiple twisted-pairs (212) orwavelengths (λ) of the cable according to a current parameter policy.

The parameter policy changer (722) represents programmed instructionsthat, when executed, cause the processing resources (702) to changeparameters, in real-time. The new parameters are used to create newdesired cable configurations that specify how to utilize the multipletwisted-pairs (212) or wavelengths (λ) within the cable (104, 206, 216,306) according to a change parameter policy. The traffic demand policyspecifier (724) represents programmed instructions that, when executed,cause the processing resources (702) to manage, in real-time, themultiple twisted-pairs or wavelengths of the cable according to atraffic demand policy.

Further, the memory resources (704) may be part of an installationpackage. In response to installing the installation package, theprogrammed instructions of the memory resources (704) may be downloadedfrom the installation package's source, such as a portable medium, aserver, a remote network location, another location, or combinationsthereof. Portable memory media that are compatible with the principlesdescribed herein include DVDs, CDs, flash memory, portable disks,magnetic disks, optical disks, other forms of portable memory, orcombinations thereof. In other examples, the program instructions arealready installed. Here, the memory resources may include integratedmemory such as a hard drive, a solid state hard drive, or the like.

In some examples, the processing resources (702) and the memoryresources (702) are located within the same physical component, such asa server, or a network component. The memory resources (704) may be partof the physical component's main memory, caches, registers, non-volatilememory, or elsewhere in the physical component's memory hierarchy.Alternatively, the memory resources (704) may be in communication withthe processing resources (702) over a network. Further, the datastructures, such as the libraries, may be accessed from a remotelocation over a network connection while the programmed instructions arelocated locally. Thus, the managing system (700) may be implemented on auser device, on a server, on a collection of servers, or combinationsthereof.

The managing system (700) of FIG. 7 may be part of a general purposecomputer. However, in alternative examples, the managing system (700) ispart of an application specific integrated circuit.

Aspects of the present systems and methods are described herein withreference to flowchart illustrations and/or block diagrams of methods,apparatus (systems), and computer program products according to examplesof the principles described herein. Each block of the flowchartillustrations and block diagrams, and combinations of blocks in theflowchart illustrations and block diagrams, may be implemented bycomputer usable program code. The computer usable program code may beprovided to a processor of a general purpose computer, special purposecomputer, or other programmable data processing apparatus to produce amachine, such that the computer usable program code, when executed via,for example, the processors of a number of computing devices describedherein such as, for example, node one (102-1) and node two (102-2), themanaging system (106, 316)), the TCOP (304), the multi-channel port(302) other programmable data processing apparatus, or combinationsthereof, implement the functions or acts specified in the flowchartand/or block diagram block or blocks. In one example, the computerusable program code may be embodied within a computer readable storagemedium; the computer readable storage medium being part of the computerprogram product. A computer readable storage medium is distinguishedherein apart from a computer readable signal medium, the latter notbeing a physical, tangible, or non-transitory medium. Thus, in oneexample, the computer readable storage medium is a non-transitorycomputer readable medium.

The specification and figures describe methods and systems for managingmultiple channels of a cable. The systems and methods includeidentifying a number of Ethernet links to utilize a number of channelsof a cable based on a number of capabilities and a number of policies ofa number of media access controllers (MACs) and a number of physicallayer entities (PHYs), determining a number of Ethernet link types to beconfigured for the cable based on the capabilities and policies of theMACs and PHYs, negotiating a number of parameters to allow multi-channelports of a number of nodes connected to the cable to establishcommunications through the Ethernet links based on the determinedEthernet link types and the utilized channels, and managing, inreal-time, the cable configuration describing the MACs to be supportedby the channels within the cable based on the policies. These methodsand systems for managing multiple channels of a cable may have a numberof advantages, including provision of a communications through a numberof channels within a cable that are more energy efficient and maintain atraffic demand

The preceding description has been presented to illustrate and describeexamples of the principles described. This description is not intendedto be exhaustive or to limit these principles to any precise formdisclosed. Many modifications and variations are possible in light ofthe above teaching.

What is claimed is:
 1. A method for managing multiple Ethernet links ona single cable comprising: identifying the multiple Ethernet links onthe single cable based on capabilities and policies of media accesscontrollers (MACs) and physical layer entities (PHYs), wherein eachEthernet link of the multiple Ethernet links utilizes one or morechannels of the single cable; determining Ethernet link types to beconfigured for the single cable based on the capabilities and thepolicies of the MACs and the PHYs; for each of the multiple Ethernetlinks, negotiating parameters based on a corresponding determinedEthernet link type and the one or more channels utilized by a respectiveEthernet link, wherein negotiating the parameters comprises exchangingcapabilities between two nodes connected to the single cable using atleast one or more next page messages, wherein the at least one or morenext page messages comprise an Organizationally Unique Identifier (OUI),an operation code indicating whether a node is capable of operatingmultiple Ethernet links on the single cable, and one or moreuser-defined codes specific to the operation code; and managing, in realtime, the multiple Ethernet links within the single cable based on thepolicies, wherein managing the respective Ethernet link comprisespowering off one or more MACs and PHYs corresponding to a particularchannel based at least on traffic demand.
 2. The method of claim 1, inwhich managing the respective Ethernet link comprises powering the oneor more channels of the single cable on or off based on the policies. 3.The method of claim 2, in which the policies comprise a traffic demandpolicy, a specific time policy, a power conservation policy, a currentparameter policy, a change parameter policy, or combinations thereof. 4.The method of claim 1, further comprising determining a length of thesingle cable to determine the Ethernet link types to utilize per cableto allow the two nodes to establish communications.
 5. The method ofclaim 1, in which determining the corresponding Ethernet link typecomprises determining if the corresponding Ethernet link type is acentral management or a port management.
 6. The method of claim 5, inwhich the central management manages the respective Ethernet link at asub-port level by sending specific messages and control messages to thetwo nodes to negotiate the parameters, in which negotiating theparameters comprises finding a best match of a set of parameters of eachend of the single cable.
 7. The method of claim 5, in which the portmanagement assigns one channel to negotiate the parameters.
 8. Themethod of claim 1, in which the method is performed by a centralmanaging device separate from the two nodes, in which the centralmanaging device sends configuration data to both of the two nodes basedon the identified multiple Ethernet links to utilize, the determinedEthernet link types, and the negotiated parameters to configure bothends of the single cable.
 9. A system for managing multiple Ethernetlinks on a single cable comprising: a processor; a storage devicecoupled to the processor and storing instructions that when executed bythe processor cause the processor to perform a method, the methodcomprising: identifying the multiple Ethernet links on the single cablebased on capabilities and policies of media access controllers (MACs)and a physical layer entities (PHYs), wherein each Ethernet link of themultiple Ethernet links utilizes one or more channels of the singlecable; determining Ethernet link types for the single cable based on thecapabilities and the policies of the MACs and the PHYs; for each of themultiple Ethernet links, negotiating parameters based on a correspondingdetermined Ethernet link type and the one or more channels utilized by arespective Ethernet link, wherein negotiating the parameters comprisesexchanging capabilities between two nodes connected to the cable usingat least one or more next page messages, wherein the at least one ormore next page messages comprise an Organizationally Unique Identifier(OUI), an operation code indicating whether a node is capable ofoperating multiple Ethernet links on the single cable, and one or moreuser-defined codes specific to the operation code; and managing, in realtime, the multiple Ethernet links within the single cable based on thepolicies, wherein managing the respective Ethernet link comprisespowering off one or more MACs and PHYs corresponding to a particularchannel based at least on traffic demand.
 10. The system of claim 9,wherein the policies comprise a traffic demand policy, a specific timepolicy, a power conservation policy, a current parameter policy, achange parameter policy, or combinations thereof.
 11. The system ofclaim 9, wherein determining the corresponding Ethernet link typecomprises determining if the corresponding Ethernet link type is acentral management or a port management.
 12. The system of claim 11, inwhich the central management manages the respective Ethernet link at asub-port level by sending specific messages and control messages to thetwo nodes connected to the ends of the single cable to negotiate theparameters, in which negotiating the parameters comprises finding a bestmatch of a set of parameters of each end of the single cable.
 13. Thesystem of claim 11, in which the port management assigns one channel ofthe one or more channels to negotiate the parameters.
 14. The system ofclaim 9, wherein the method comprises determining a length of the singlecable to determine the Ethernet link types to utilize per cable to allowthe two nodes to establish communications.
 15. A computer programproduct for managing multiple Ethernet links of a single cable,comprising: a non-transitory computer readable storage medium, saidnon-transitory computer readable storage medium comprising computerreadable program code embodied therewith, said computer readable programcode comprising program instructions that, when executed, causes aprocessor to: identify the multiple Ethernet links on the single cablebased on capabilities and policies of media access controllers (MACs)and physical layer entities (PHYs) connected to the single cable,wherein each Ethernet link of the multiple Ethernet links utilizes oneor more channels of the single cable; determine Ethernet link types forthe single cable based on the capabilities and the policies of the MACsand the PHYs; for each of the multiple Ethernet links, negotiateparameters based on a corresponding determined Ethernet link type andthe one or more channels utilized by a respective Ethernet link, whereinnegotiating the parameters comprises exchanging capabilities between twonodes connected to the single cable using at least one or more next pagemessages, wherein the at least one or more next page messages comprisean Organizationally Unique Identifier (OUI), an operation codeindicating whether a node is capable of operating multiple Ethernetlinks on the single cable, and one or more user-defined codes specificto the operation code; and manage, in real time, the multiple Ethernetlinks within the single cable based on the policies, wherein managingthe respective Ethernet link comprises powering off one or more MACs andPHYs corresponding to a particular channel based at least on trafficdemand.
 16. The product of claim 15, further comprising computerreadable program code comprising program instructions that, whenexecuted, cause said processor to determine a length of the single cableto determine the MACs to utilize per Ethernet link to allow the twonodes to establish communications.